Skip to content

SwiftNIO Extras vulnerable to improper detection of complete HTTP body decompression

High severity GitHub Reviewed Published Sep 20, 2022 in apple/swift-nio-extras • Updated Jun 19, 2023

Package

swift github.com/apple/swift-nio-extras (Swift)

Affected versions

>= 1.11.0, < 1.14.0
>= 1.10.0, < 1.10.3
< 1.9.2

Patched versions

1.14.0
1.10.3
1.9.2

Description

SwiftNIO Extras provides a pair of helpers for transparently decompressing received HTTP request or response bodies. These two objects (HTTPRequestDecompressor and HTTPResponseDecompressor) both failed to detect when the decompressed body was considered complete. If trailing junk data was appended to the HTTP message body, the code would repeatedly attempt to decompress this data and fail. This would lead to an infinite loop making no forward progress, leading to livelock of the system and denial-of-service.

This issue can be triggered by any attacker capable of sending a compressed HTTP message. Most commonly this is HTTP servers, as compressed HTTP messages cannot be negotiated for HTTP requests, but it is possible that users have configured decompression for HTTP requests as well. The attack is low effort, and likely to be reached without requiring any privilege or system access. The impact on availability is high: the process immediately becomes unavailable but does not immediately crash, meaning that it is possible for the process to remain in this state until an administrator intervenes or an automated circuit breaker fires. If left unchecked this issue will very slowly exhaust memory resources due to repeated buffer allocation, but the buffers are not written to and so it is possible that the processes will not terminate for quite some time.

This risk can be mitigated by removing transparent HTTP message decompression. The issue is fixed by correctly detecting the termination of the compressed body as reported by zlib and refusing to decompress further data.

References

@Lukasa Lukasa published to apple/swift-nio-extras Sep 20, 2022
Published by the National Vulnerability Database Sep 21, 2022
Published to the GitHub Advisory Database Jun 7, 2023
Reviewed Jun 7, 2023
Last updated Jun 19, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.089%
(39th percentile)

Weaknesses

CVE ID

CVE-2022-3252

GHSA ID

GHSA-773g-x274-8qmf

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.